Improvement in grate-bars for furnaces



J. ASHCROFT Grate-Bars for Furnaces No. 197,510. Patented Nov. 27, 1877.

UNITED TATES PAT/ENT OFFICE.-

JOHN ASHCROFT, OF

BROOKLYN, NEW YORK, ASSIGNOR TO SARAH JANE ASHCROFT, OF SAME PLACE. A

IMPROVEMENT IN GRATE-BARS FOR FURNACES.

Specification forming part of Letters Patent No. 197,510, dated November27, 1877; application filed June 15, 1877.

Y To all whom it may concern:

front, and rear walls of a furnace, and of the improved grate-bar andsupports and guides. Fig. 2 is a plan view of a furnace and gratebars;and Fig. 3 is a front view of the same, showing, in addition, a hollowbar on a crosssection behind the front wall of the furnace.

My invention consists in a grate-bar so arranged as to rock or revolve,said grate-bar being triangular in its general conformation, and across-section of which on its outline describing a triangle or a figurewith three sides, the intersections of the sides being sharp or slightlyrounded.

In the drawing, A represents the four walls of an ordinary furnace; B BB, grate-bars, which are. triangular or three-sided on theircross-section, and maybe sharp or slightly rounded at the intersectionof the sides. 0 O O O are circular recesses or holes, into or throughwhich the grate-bars are passed. D D are plates, attached to the rearand front walls, or making part thereof, in which the circular recessesor holes are sunk or perfosupport. and assist in guiding the bars.

In operation, the bars being placed in posi tion, the front ends extendthrough the front plate D to the outside of the furnace, where they maybe readily reached and revolved by the application of a key or wrench.

I The shape of the bar results in four great advantages:

First, the bar in position presents one side to support the body of thefuel. Any ashes 'or clinkers that pass between the interstices of thebars must necessarily fall, because the width of the intersticesconstantly increases toward the bottom.

Second, the circulation of air upthrough or between the bars is free,because of the shape of the interstices and the decrease of friction.

Third, as a resultant from the free circulation of air the bars do notheat so quickly or so much.

Fourth, nearly or not quite one-half of the material in the bar issaved.

This saving may be increased by making this bar hollow, and perforatingits shell with holes, as shown in Fig. 3, the circulation of air boththrough the bar and on its sides being so free as to prevent itsdestruction by the heat.

Having described any invention and its application, what I claim as new,is-

A revolving or rocking grate-bar, a cross section of which shows theoutline of v a triangle or with three sides, the intersectionsthereofbeing sharp or slightly-rounded edges.

JOHN ASHCROFT.

Witnesses:

PHILIP BOTTMAN, E. BQBARNUM.

